In an electrical power system, electrical transformers are often used to connect two different voltage systems or buses in an electrical substation. An electrical transformer is an electromagnetic device that transfers electrical energy from one circuit to another through mutual inductance. During this energy transfer, electricity may be converted from one voltage level or type to another. The transformer typically includes two windings, the primary winding connected to the source of voltage and the secondary winding connected to the load. The windings are wound around a silicon steel laminated core which provides a path for the flow of magnetic flux to achieve the transfer of energy from the primary to the secondary winding. On the other hand, an autotransformer has only one winding, portions of which act as both the primary and secondary sides of the transformer. The autotransformer has typically three taps where electrical connections are made, such as a primary tab, a secondary tab, and a neutral tab. Autotransformers can be configured to be smaller, lighter, and cheaper than typical dual-winding transformers.
In traditional metering applications, isolation transformers are typically used due to their robustness, and due to the requirement of high thermal burden and accuracy, and because such transformers are used in connection with both metering and power supply portions of an electrical meter. However, such isolation transformers are heavy, expensive, and difficult to maintain (add, remove, or replace) by service technicians. Even if other types of transformers are used, there is no convenient way to connect or disconnect such transformers from a system, in particular systems in which such transformers are added into an existing circuit.
For these and other reasons, improvements are desirable.